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Python - how do I concatenate the name:value pairs of request headers with the tab (\t) separator

Python - how do I concatenate the name:value pairs of request headers with the tab (\t) separator such that name field is all in lower case?

Below are the points to be considered.

Get the first header value for the name.
Trim the leading and trailing white spaces.
Replace all repeated white spaces with a single space.
Concatenate the name, value pairs with the tab (\t)separator(name field is all in lower case).
Terminate the headers with another tab (\t) separator.
import re
headers ={ "Accept" : "application/vnd.accept_header-status.v11+json", "Content-Type" : "application/vnd.content-type_header.v11+json" }
canonicalize_headers='\t'.join(h for h in headers)
print(canonicalize_headers)

Sample input:

Host: akaa-xxxxxxxxxxxxxxxx-xxxxxxxxxxxxxxxx.aa-dev.net.net
 x-a: va
 x-c: "      xc        "
 x-b:    w         b

Sample Output:

POST\thttp\takaa-xxxxxxxxxxxxxxxx-xxxxxxxxxxxxxxxx.aa-dev.net\t
 /sample-api/v1/property/?fields=x&format=json&cpcode=1234\tx-a:va\tx-b:w b\tx-c:" xc "\t\t\t

need to create a post request with signing headers

Solution:

From what I have understood, what you are looking for is:

def clean(headers):
    for k, v in headers.items:
        k = re.sub(r"\s+", " ", k.strip())
        yield f"{k.lower()}\t{v}"

canonicalize_headers = "\t".join(clean(headers))